Contemporary helicopters often exhibit a low efficiency of the drive system. In addition, the drive is often very loud.
The drive train consists of one or more internal combustion engines and a mechanical main gear unit. Turbine shaft drives or reciprocating piston engines are frequently used.
DE 10 2008 028 866 A1 as well as WO 2009/153236 A2 describe a helicopter with a wobble plate actuator.